package com.zzy.chapter02;

import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.streaming.api.datastream.DataStreamSource;
import org.apache.flink.streaming.api.datastream.KeyedStream;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.util.Collector;

import java.util.Arrays;

public class StreamWordCount {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        DataStreamSource<String> lines = env.readTextFile("input/words.txt");
        SingleOutputStreamOperator<Tuple2<String, Long>> wordAndOne = lines.flatMap((String line, Collector<String> words) -> Arrays.stream(line.split(" ")).forEach(words::collect))
                .returns(Types.STRING)
                .map(word -> Tuple2.of(word, 1L))
                .returns(Types.TUPLE(Types.STRING, Types.LONG));
        KeyedStream<Tuple2<String, Long>, String> keyedWord = wordAndOne.keyBy(t -> t.f0);
        SingleOutputStreamOperator<Tuple2<String, Long>> keyedSum = keyedWord.sum(1);
        keyedSum.print();
        env.execute();

    }
}
